Knitting machine



R. H. LAWSQIN KNITTING MACHINE Filed Jan. 28, 1.955

INVENTOR. mwww H. m%

KNiT'lllil lG MACHINE Robert H. Lawson, Pawtuclret, R. 1., assignor toScott & Williams, incorporated, Laconia, N. HZ, a corpora tion atMassachusetts Application January 23, 19%, Serial No. 434,649

d \Clmhns. (Cl. 66-107) This invention relates to knitting machines andhas par ticuiar reference to a sinker construction suitable for knittingin which stitches are drawn behind sinker nebs.

In the knitting of ladies sheer hosiery, in particular, it has beenfound advantageous in the production of uniform loops to draw stitchesbehind the nebs of sinkers in contrast with the more usual practice ofdrawing stitches over sinker ledges in front of or inwardly of thesinker nebs. However, in the adoption of this process of drawingstitches behind the nebs, it has been found that difiiculties areencountered particularly in fine gauge machines in that at times, whenneedles were raised to tuck height, their latches were liable to crossthe top of the sinker, or drag on the side thereof, and, beingrestrained thereby, the latches would then either break the loop of yarnattempting to open the latch or, by robbing yarn from adjacent stitches.produce badly distorted stitches. Whether breakage or only distortionoccurred depended, in general, upon how tight or loose the fabric wasbeing knit. This occurred because in machines having thirtyfour or moreneedles per circumferential inch the needles and sinkers are so closelyspaced that the latch blade, being necessarily quite thin and flexible,has a tendency to cross the sinker as just mentioned, although inmachines having less needles per inch the spacing is generallysufiicient to make such crossing unlikely.

In accordance with the present invention, the rear platform of eachsinker is shortened to substantially the minimum extent necessary toinsure proper drawing of a loop, or said platform may be eliminatedentirely, the sinker being cut away to provide clearance for the needlelatch even though during the opening movement of the latch the latch maycross the plane of the sinker. Tighter fabric may thus be knit withoutbreakage, and both tight and loose fabrics may be knit without stitchdistortion.

The general object of the invention relates to the attainment in thefashion indicated of proper stitch formation particularly in fine gaugemachines, and this and other objects of the invention relatingparticularly to details of construction and operation will becomeapparent from the following description, read in conjunction with theaccompanying drawing, in which:

Figure 1 is a fragmentary sectional View in the region of the upper endof a. needle cylinder of a circular machine showing, in particular, thepositions assumed by the operating instrumentalities at the time a latchis being opened by the rise of a needle through a previously formedloop; and

Figure 2 is a similar sectional view but showing the drawing of a loopover the sinker ledge behind the mob.

The machine illustrated is of the circular revolving needle cylindertype and in the figures of the drawing the upper portion oi the needlecylinder is shown at 2, being provided with needle slots i in whichthere slide conventional latch needles 6 provided with hooks 8 andlatches ill, the latter being pivoted at 12. The needles are moved inconventional fashion through the medium of cams operating on theirbutts, not shown. A conventional sinker States Patent dial is indicatedat 14 and is surmounted by the conventional sinker cap 16 provided withthe usual sinker earns 18 for acting upon but surfaces on sinkers 20which are mounted to slide between adjacent needles in slots in thesinker dial, the inner portions of the sinkers being guided by theportion 24 of an inside sinker ring 22 entering the slots 26 in thesinkers and also providing slots 27 for the guidance of the innerportions of the sinkers.

Each of the sinkers is provided with a neb 28 which faces inwardly andoverlies the forward sinker ledge 30. At the rear of each sinker neb 28there may be provided a ledge 32 having a radial extent which issubstantially only sufficient to underlie and hold the yarn as it isdrawn. by the needles. To the rear or outside of the ledge 32 the sinkeris cut away to provide a clearance space 34 for the the free movement ofthe needle latches 10.

In the operation of the arrangement just described, referring first toFigure 2, the loops are drawn by the me dies over the ledge 32 behindthe sinker nebs 28, the ledges 32 in this operation being in approximateaxial alignment with the interiors of the needle hooks. As: will beclear from Figure 2, the ledges 32 must extend radially out wnrdly onlyto a relatively slight extent sufficient to insure that the yarn as itis drawn downwardly by the needles does not miss the ledges, the ledgespreferably being substanttially horizontal so as not to have any outwardcamn'iiug action on the yarn. Following the loop drawing movement, thesinkers are retracted slightly as the needles are raised to tuck heightand then, as the needles appreach the position where yarn is taken, thesinkers are fully retracted to cause their nebs to ride under the newlydrawn loops with resulting positioning of the yarn in the loops tosecure uniformity, the drawn loops being then ultimately located on theledges 30 inwardly of the nebs 28. The actions upon the yarns which arethus accomplished are well known and need not be described in detail.

The invention is particularly concerned with what occurs as the needlesrise following the subsequent inward movements of the sinkers. As theneedles rise to tuck height, as illustrated in Figure 1, the loopsthereon engage the latches, causing the latches to swing to openposition with ultimate clearing as the needles continue to rise toclearing height. l-leretofore, the ledges 32 have continued horizontallyoutwardly to positions substantially be yond the rear of the nebs and,under such circumstances, particularly in fine gauge machines, latcheshave moved laterally to cross and become caught on these ledges. Inaccordance with the present invention, the sinkers are cut away as at 34to provide a clearance space so that as the latches open as illustratedin Figure 1, even though they may move laterally, they cannot engage anyupper edge portions of the sinkers. It may be noted, considering Figure1, that the upper edge of the clearance 34 is shown at such positionthat if the latch 10 swung to full open position about the illustratedposition of pivot 12 the spoon of the latch might engage the upper edgeof the sinker at the clearang space 34. However, in actual practice, theswinging of the latch 10 to full open position occurs simultaneouslywith continued upward movement of the pivot point 12, the result beingthat the spoon of the latch does not swing in a circular are about theillustrated position of pivot 12 but, rather, in a somewhat oval orelliptical path rising above such hypothetical circular arc. Also, whenthe latch 10 is in a nearly horizontal position it has a minimum ofsupport from the check of the needle with a consequence that it willreadily contact any closely bounding piece, whereas when said latchachieves a more fully open position it becomes better supported by theneedle cheeks and can be more closely bounded without danger of the tipof the latch striking said boundaries. Accordingly, in actual practice,a clearance such as indicated at 34 may be provided leaving, despite theadequate clearance, a maximum amount of metal in the main body portionof the sinker to insure proper stiffness of the sinker itself. It may benoted that where the latch actually overlaps, during opening, the ledge32, this portion of the latch being closely adjacent to the pivot couldnot, except due to very excessive bending of the latch, engage thesinker. Thus, it is not required that there should be a cutaway portionof the sinker below the ledge 32.

The above discussion of the path of the spoon of the latch may befurther made clear by reference to the patent to Moss No. 2,333,667which illustrates in successive positions of opening a latch the path ofthe latch spoon.

It will be evident from the foregoing that in accordance with theinvention provision is made to prevent arresting by the upper edge of asinker of a needle latch during its opening movement and, thus, there isprevented breakage of the loops carried on the needle during the needlemovements toward clearing height.

What is claimed is:

1. In a fine gauge circular hosiery knitting machine, independentlymovable latch needles, and independently movable sinkers cooperatingwith the needles for the formation of stitches, each of said sinkerscomprising a neb and a ledge of short radial extent located behind saidneb and providing a horizontal platform having a radial extentsubstantially only sutficient to underlie and hold yarn as loops aredrawn by the needles, said sinker being cut away substantiallyvertically behind said ledge and throughout substantially the regionadjacent to the path of the outer portion of a needle latch duringopening movement thereof under the action of yarn extending across theneedle behind said neb.

2. A sinker adapted for use in a fine gauge circular hosiery knittingmachine in association with latch needles, said sinker comprising a neband a ledge of short radial extent located behind said neb and providinga horizontal platform having a radial extent substantially onlysufiicient to underlie and hold yarn as loops are drawn by the needles,said sinker being cut away substantially vertically behind said ledgethrough substantially the region adjacent to the path of the outerportion of a needle latch during opening movement thereof under theaction of yarn extending across the needle behind said neb.

3. In a fine gauge circular hosiery knitting machine, independentlymovable latch needles, and independently movable sinkers cooperatingWith the needles for the formation of stitches, each of said sinkerscomprising a neb and a ledge of short radial extent located behind saidneb and providing a horizontal platform having a radial extentsubstantially only sufiicient to underlie and hold yarn as loops aredrawn by the needles, said sinker being cut away substantiallyvertically behind said ledge from a point substantially incircumferential alignment with the point of an adjacent needle hook asthe needle rises throughout substantially the region adjacent to thepath of the outer portion of a needle latch during opening movementthereof under the action of yarn extending across the needle behind saidneb.

4. A sinker adapted for use in a fine gauge circular hosiery knittingmachine in association with latch needles, said sinker comprising a neband a ledge of short radial extent located behind said neb and providinga horizontal platform having a radial extent substantially onlysufficient to underlie and hold yarn as loops are drawn by the needles,said sinker being cut away substantially vertically behind said ledgefrom a point substantially in circumferential alignment with the pointof an adjacent needle hook as the needle rises throughout substantiallythe region adjacent to the path of the outer portion of a needle latchduring opening movement thereof under the action of yarn extendingacross the needle behind said neb.

Lawson et al. May 3, 1938 Moss Nov. 3, 1943

